Stethoscope with convertible receiver



' Dec. 14, 1965 o. R. ALLEN 3,223,195

STETHOSCOPE WITH CONVERTIBLE RECEIVER Filed Dec. 31, 1962 D QEM 19. A4454,

IN V EN T 0R.

United States Patent 3,223,195 STETHOSCOPE WITH CONVERTIBLE RECEIVER Derek R. Allen, Downey, Calif., assignor to Allen Medical Instrument Corporation, Glendale, Calif., a corporation of California Filed Dec. 31, 1962, Ser. No. 248,494 Claims. (Cl. 18124) This invention relates to stethoscopes and has as its general object to provide a stethoscope having an improved convertible receiver which provides maximum versatility in auscultation (listening to the sounds within a human body).

In particular, the invention provides a double-ended receiver having a large bell at one end, a small bell at its opposite end, and a core which is shiftable to selectively implement the operative condition of either of these bells.

A further object is to provide such a stethoscope receiver wherein the core embodies a valve element for selectively directing the path of air flow through the receiver and a diaphragm (for high frequency sound reception) which is fixed to the valve element and disposed in the large bell of the receiver for shifting movements between an operative position for chest contact and a retracted position in which the large bell becomes operative as a receiver.

A further object is to provide an improved stethoscope receiver embodying a diaphragm for diaphragm-type reception through direct skin contact, a large bell for extended low frequency range reception of sound, and a small bell for high amplitude low frequency sound reception, particularly adapted for use on bony chests and in pediatrics and for listening to small localized areas of a chest.

The terms high and low frequency are to be understood as referring generally to the upper and lower portions (e.g. above and below an intermediate frequency of about 100 cycles) in the range of physiological and pathological sound (usually considered to extend from about 50 cycles up to about 1200 cycles). It will also be understood that the frequencies that can be received will have considerable overlap in the respective settings.

A further object is to provide a stethoscope having improved double-ended receiver mechanism wherein a rotatable core embodies at one end a valve element having a small-bell reception face, and at its other end a diaphragm which provides a large-area reception face, said valve element being operative, upon rotation of the core, to selectively connect either of said faces to a port to which an air-column sound transmitting tube is connected.

A further object is to provide a stethoscope having improved binaural adjustment mechanism, combined with means for lightly spring-loading the binaurals against a wearers ears.

Other objects and advantages will become apparent in the ensuing specification and appended drawing in which:

FIG. 1 is a plan view of a stethoscope embodying the improvements of my invention;

FIG. 2 is an end view of the binaural spring yoke;

FIG. 3 is a plan view of the yoke;

FIG. 4 is a detail view, partially in axial section and partially in elevation, of the receiver in small-bell operational adjustment;

FIG. 5 is a fully section-elevation view of the receiver, with the core adjusted to the large-bell operational position;

FIG. 6 is a plan view of the receiver viewed at the small bell end;

FIG. 7 is an axial sectional view of the receiver, taken in the plane of the transmission tube, with the core adjusted to the large-bell operational position;

FIG. 8 is a cross sectional view through the central portion of the receiver, with the core adjusted to the small bell operational position;

FIG. 9 is an an axial sectional view through the receiver, in the same position of adjustment;

FIG. 10 is a detail view of the valve element of the valve plug; and

FIG. 11 is a detail outer end view of the valve element.

DESCRIPTION Referring now to the drawings in detail, and in particular to FIG. 1, there is shown therein, as an example of one form in which the invention may be embodied, a stethoscope comprising, in general, a receiver A, a binaural unit B, and a flexible transmission tube C.

Receiver A (FIG. 7) comprises a bell housing 15 having at one end an integral small bell 16 and at its opposite end an integral large bell 17, the latter having a generally cylindrical counterbore 18. The bells 16 and 17 are joined by a slightly flaring intermediate barrel 19. The bottom of the small bell 16 is defined by an annular web 20, from which a cylindrical valve shell 21 projects axially to approximately the plane of an annular shoulder 22 which provides a seat for the bottom of the large bell 17.

At the bottom of large bell 17 is a receiving face defined by a diaphragm 25, consisting of a circular disc of thin sheet material having a central port 26 mounted within the shallow rim 27 of a diaphragm plate 28, and secured thereto, e.g. by a wedging fit (or by a conventional retaining ring). Plate 28 has in its rear face an annular groove 29 which receives the end of the valve shell 21 when the receiver core is adjusted to the largebell position. In this position, the diaphragm plate 28 is seated against the shoulder 22 as indicated in FIG. 5. The forward face of diaphragm plate 28 is slightly dished, so that only the periphery of the diaphragm 25 rests against the plate, a very shallow diaphragm chamber 30 being thus defined between such forward face and the rear face of diaphragm 25, for diaphragm transmission of sounds.

Secured to the rear face of diaphragm plate 28 is a cylindrical valve element 31 (FIG. 10) which functions as a rotatable valve plug and as an axially slidable valve piston. Valve plug 31 has a squared inner end 32 secured to the center of diaphragm plate 28 by a pair of screws 33. In the inner end of the plug is an L-shaped valve passage 34 (FIG. 7) including an axial port communicating with the port 26 of diaphragm 25 through a central passage 35 in the valve disc 28, and a radial arm which is adapted to be registered with a radial communication port 36 in a boss 37 formed as an enlarged portion of Web 2t). One end of the transmission tube C is coupled to port 36 through a nipple 38. Thus, in the position of the core as shown in FIG. 7, the air column of the transmission tube C is coupled to the air chamber 39 defined within the large bell 17, for large bell auscultation.

In its outer end, valve plug 31 has a receiving face defining a shallow conical recess 41, and an L-shaped valve passage 43. Valve passage 34 has a short axial arm communicating with the bottom of recess 41 and a radial arm which is adapted to communicate with the coupling port 36 when the core is in the small-bell operational position shown in FIG. 9. In that position the core 31 provides the bottom of a small bell chamber 40 for reception of sounds from a small local area, when the small bell is pressed against the chest.

Referring now to FIG. 11, in which the valve plug 31 is viewed at its outer end, the radial arms of the respective L-passages 34 and 43 are seen to be disposed at 90 degrees angular displacement from one another. It will also 'be noted, in FIG. 7, that the two passages, while disposed in closely adjacent relation along the axis of the valve 31, are separated from one another by a thin web of material in the center of the plug, and the radial arms of the respective passages are offset from one another along the axis of the valve plug. Thus, the passage 34 provides communication (to transmission tube C) only from the diaphragm 25 and large bell chamber 39; whereas the passage 43 provides communication only from the small bell chamber 40. Also, in order to shift from one communication t the other, it is necessary to shift the valve plug 31 axially and to rotate it through 90 degrees.

To determine the two positions, and to fix the core in the respective positions, the valve plug 31 is provided in its periphery (FIG. 10) with a bayonet slot 46 including an arm extending parallel to its axis toward the inner end of the plug and terminating in a detent recess 47, and a circumferential arm extending from the other end of this axial arm approximately 90 degrees and terminating (FIG. 8) in a detent recess 48. A detent ball 49 is engaged in the recess 46 and is caged in a bore 50 in a radial boss 51 diametrically opposite the communication port 36 in the bell housing 15. A coil spring 52, engaged under compression between the bottom of the bore 50 and the ball 4%, spring-loads the latter for yielding latching engagement in the respective recesses 47, 48, thereby latching the core in its positions of axial and circumferential adjustment, preventing either axial or circumferential shifting movement until overcome by manual manipulation of the core. The bayonet groove 46 has a third detent depression 53 at the bend between its axial and circumferential arms, for latching the core in the diaphragm position of FIG. 4.

At its outer end, valve plug 31 is provided with a marginal bead 42 which is adapted to engage the web 2%) of the receiver housing to limit the forward projection of the core at the position where the diaphragm is flush with the rim of the large bell 17. This prevents escape of the core from the housing in the event that excessive pressure is inadvertently applied to the outer end of the valve core 31, in shifting it to the diaphragm operational position of FIG. 4.

Binaural B comprises a T-fitting 55 coupled to the other end of transmission tube C, a pair of flexible branch tubes 56 coupled to the respective sides of fitting 55; a pair of binaurals 57, of metal or stiff plastic tubing, each having one end inserted into a corresponding end of a respective branch tube 56 and each having a conventional ear plug 58 at its other end; and the improved spring yoke 59, comprising a yoke portion of spring metal in ribbon form and a pair of spring clamp sleeves 60, integral with its respective ends. Clamp sleeves 60 encircle the respective binaurals 57 and are in yielding constrictive frictional engagement therewith so as to permit the tubes to be rotated and to hold them in position of rotational adjustment. The flexibility of branch tubes 56 is such that they can rotate with the ends of binaurals 57 to which they are attached, torsionally adjusting themselves to the rotational adjustment. The yoke 59 is contoured to provide the proper forked configuration of the pair of tubes 56, and provides support and protection for these tubes. The clamp sleeves 60 are joined to the respective ends of the arms of yoke 59 by integral webs 61 which are bent at right angles to the respective arms and project in opposite directions in a common plane adjacent to plane of the edges of the yoke arms at one side of the yoke. The sleeves 60 are rolled in such a direction as to position them generally in the general plane of the yoke 59 (FIG. 2).

The yoke provides a gentle spring-loading of the ear plugs 58 toward one another for snug seating in the ear canals. The clamp sleeves 60 provide a gentle grasp My improved receiver provides three positions of operations, two at the large bell end, shown in FIGS. 4 and 7, and one at the small bell end, shown in FIG. 9. These three operational positions may be referred to as follows:

(a) Diaphragm operation is effected with the receiver as shown in FIG. 4, the core being adjusted to the position of rotational adjustment shown in FIG. 7 but being pushed forwardly to place the diaphragm 25 in the plane of the rim of large bell 17. The width of port 36 is such that the passage 34 will communicate with the port 36 adjacent its forward side as indicated in dotted lines in FIG. 7. Diaphragm operation provides increased sensitivity to high frequency sounds. It is ideal for detecting split second sounds, high pitched murmurs, and fine rales (chest rattles and other extraneous or abnormal sounds accompanying breathing).

(b) Large bell operation is illustrated in FIG. 7. The position of rotational adjustment of the core is the same as for diaphragm operation, but the core is shifted rearwardly to provide the large bell chamber 39. The shift from diaphragm to large bell operation is accomplished simply by applying pressure to the center of the diaphragm, causing it to collapse below the large bell rim. Passage 34 communicates with port 36 adjacent to its rear side as shown in full lines in FIG. 7. Large bell operation has the recognized advantage of auscultation of a large chest area. The invention provides for shifting from diaphragm to large bell operation without moving the stethoscope from the chest to change receivers, thus providing for auscultation in a full range of frequencies.

(c) Small bell operation is disclosed in FIG. 9. Adjustment to this position is made from the diaphragm position of FIG. 4 by rotating the receiver core degrees (counterclockwise as viewed from the small bell end) to bring the passage 43 into communication with port 36. The core, being in the forwardly-displaced position, provides the bottom of the small bell chamber 40 for reception of sounds from a small localized area. Small bell operation provides for high amplitude reception for use in pediatrics, on bony chests, or for concentrating the listening to a small area.

I claim:

1. A stethoscope receiver comprising: a housing embodying a small bell at one end, means defining a central cylindrical valve bore coaxial with said bell, and a radial communication port intersecting said bore; a core comprising a diaphragm at one end and a valve plug having a small bell receiving face at its other end, said valve plug having a first valve passage communicating with the center of the diaphragm and having in its lateral wall a mouth positioned to register with said communication port, said valve plug having a second valve passage communicating with said small bell receiving face and having in its lateral wall a mouth angularly displaced from the mouth of said first valve passage and adapted to register with said communication port upon rotation of said core said housing having a large bell at its other end, and said core being axially shiftable to position said diaphragm selectively in the plane of the rim of said large bell, for diaphragm reception of sounds, and at the bottom of said large bell, to provide a large-bell chamber for air-transmission of sounds.

2. A stethoscope receiver comprising: a housing embodying a large bell at one end, a small bell at its other end, means defining a central cylindrical valve bore and a radial communication port intersecting said bore, said bore being coaxial with said bells; a cylindrical valve plug having a large-bell receiving face at one end and a small bell receiving face at its other end, said valve plug having a first valve passage communicating with the center of said large bell receiving face and having in its lateral wall a mouth positioned to register with said communication port, said valve plug having a second valve passage communicating with said small bell receiving face and having in its lateral wall a mouth angularly displaced from the mouth of said first valve passage and adapted to register with said communication port upon rotation of said core.

3. A stethoscope receiver as defined in claim 2, wherein said valve passages are of L-shape.

4. A stethoscope receiver comprising: a housing embodying a small bell at one end, means defining a central cylindrical valve bore, said bore being coaxial with said bell and a radial communication port intersecting said bore; a core comprising a diaphragm at one end and a valve plug having a small bell receiving face at its other end, said valve plug having a first valve passage communicating with the center of the diaphragm and having in its lateral Wall a mouth positioned to register with said communication port, said valve plug having a second valve passage communicating with said small bell receiving face and having in its lateral wall a mouth angularly displaced from the mouth of said first valve passage and adapted to register with said communication port upon rotation of said core; and detent means for yieldingly latching said core in each of its positions of rotational adjustment, said detent means comprising a circumferential groove in the lateral wall of said plug, said groove having ball-receiving depressions at its respective ends, and a spring-loaded ball mounted in said housing, engaged in said groove, and adapted to seat in said depressions with a detent latching action.

5. A stethoscope receiver comprising: a housing embodying a small bell at one end, means defining a central cylindrical valve bore and a radial communication port intersecting said bore; a core comprising a diaphragm at one end and a valve plug having a small bell receiving face at its other end, said valve plug having a first valve passage communicating with the center of the diaphragm and having in its lateral wall a mouth positioned to register with said communication port, said valve plug having a second valve passage communicating with said small bell receiving face and having in its lateral wall a mouth angularly displaced from the mouth of said first valve passage and adapted to register with said communication port upon rotation of said core, said core being shiftable to position said diaphragm selectively in the plane of the rim of said large bell, for diaphragm reception of sounds, and at the bottom of said large bell, to provide a largebell chamber for air-transmission of sounds; and detent means for yieldingly latching said core in each of its positions of rotational adjustment, said detent means comprising a circumferential groove in the lateral wall of said plug, said groove having ball-receiving depressions at its respective ends, and a spring-loaded ball mounted in said housing, engaged in said groove, and adapted to seat in said depressions with a detent latching action.

References Cited by the Examiner UNITED STATES PATENTS 693,487 2/1902 Bowles 181-24 717,898 l/1903 McCully 181-24 821,315 5/1906 Root 181-24 860,906 7/1907 Dittmar 18124 874,092 12/ 1907 Liverpool 18124 2,419,471 4/ 1947 Thibos. 2,513,827 7/1950 Tynan 18124 2,633,205 3/1953 Rayder 18124 2,719,594 10/1955 Smithline 18124 2,722,989 11/1955 Tynan 18124 3,035,656 5/1962 Kebel 181-24 3,109,508 11/1963 Cefaly 18124 LEYLAND M. MARTIN, Primary Examiner.

LEO SMILOW, Examiner. 

1. A STETHOSCOPE RECEIVER COMPRISING: A HOUSING EMBODYING A SMALL BELL AT ONE END, MEANS DEFINING A CENTRAL CYLINDRICAL VALVE BORE COAXIAL WITH SAID BELL, AND A RADIAL COMMUNICATION PORT INTERSECTING SAID BORE; A CORE COMPRISING A DIAPHRAGM AT ONE END AND A VALVE PLUG HAVING A SMALL BELL RECEIVING FACE AT ITS OTHER END, SAID VALVE PLUG HAVING A FIRST PASSAGE COMMUNICATING WITH THE CENTER OF THE DIAPHRAGM AND HAVING IN ITS LATERAL WALL MOUTH POSITIONED TO REGISTER WITH SAID COMMUNICATION PORT, SAID VALVE PLUG HAVING A SECOND VALVE PASSAGE COMMUNICATING WITH SAID SMALL BELL RECEIVING FACE AND HAVING IN ITS LATERAL WALL A MOUTH ANGULARLY DISPLACED FROM THE MOUTH OF SAID FIRST VALVE PASSAGE AND ADAPTED TO REGISTER WITH SAID COMMUNICATION PORT UPON ROTATION OF SAID CORE SAID HOUSING HAVING A LARGE BELL AT AT ITS OTHER END, AND SAID CORE BEING AXIALLY SHIFTABLE TO POSITION SAID DIAPHRAGM SELECTIVELY IN THE PLANE OF THE RIM OF SAID LARGE BELL, FOR DIAPHRAGM RECEPTION OF SOUNDS, AND AT THE BOTTOM OF SAID LARGE BELL, TO PROVIDE A LARGE-BELL CHAMBER FOR AIR-TRANSMISSION OF SOUNDS. 